<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0px;
            padding: 0px;
        }
        div{
            width: 300px;
            height: 300px;
            background-color: #ccc;
            align-items: center;
            margin: 50px;
            display:flex; 
            /* flex-direction: row;
            flex-wrap: wrap; */
            /* flex-flow: row wrap; */
        }
        div p{
            /* width: 88px; */
            flex: 1;
            height: 80px;
            background-color: red;
            /* border: 1px solid red; */
            /* margin-left: 10px; */
            /* float: left; */
        }
        div p:nth-child(2){
            /* flex:2; */
            flex:initial;
            width: 150px;
            background-color: blue;
        }
        /*
        div:300px-->300*50%=150px    div缩小，但是p的边框个外边距不会缩小
        p:88+2+10-->88*50%+2+10=56px(正常)
        伸缩盒子以后：（？）*50%+2+10=50px   会改变内容取的宽度
        */
    </style>
</head>
<body>
    <div>
        <p>p1</p>
        <p>p2</p>
        <p>p3</p>
    </div>
</body>
</html>